1. Field of the Invention
The present invention relates to a combining structure between a lamp socket and a lamp base of Christmas lights for improving the stable combination between the lamp socket and the lamp base.
2. Description of the Related Art
A conventional Christmas light generally comprises of a lamp bulb, a lamp base and a lamp socket, therein the lamp base is first combined together with the lamp bulb and then inserted into the lamp socket so as to maintain the combined relationship between the lamp base and the lamp socket by the friction force between their surfaces. However, in a case that the lamp base and the lamp socket are made of the recycled plastic materials, it is difficult to control the dimensional tolerance of tight fit between them; therefore, it results a very unstable friction force. Often, there are defeats either too tight or too loose between the lamp base and the lamp socket. If it is too loose, they are easy to be dislodged from each other and the contact resistance becomes high enough to cause a latent hazard of fire. On the contrary, if it is too tight, it will affect the assembling speed and thereafter the advantages of replacing burned out lamps.
In view of the fact that the existing structure between the conventional lamp base and lamp socket is controlled by the dimensional tolerance, it is difficult to achieve tight fit because the materials used in every batch are different. Furthermore, due to the purpose of reducing the production costs, the plastic materials generally used are recycled materials, of which the quality is variable, so as to cause the appropriate friction force obtained from the controlling dimensional tolerance becomes meaningless.
Therefore, the object of the present invention is to provide an innovated structure between a lamp socket and a lamp base of Christmas lights for supporting a stable combination between them.
According to the present invention, the lamp base is integrally formed at its end a long friction stub which has an expanded forehead, and the lamp socket is formed at its end inserted with lead wires a positioning hole. When the lamp base and the lamp socket are combined together, it is required to first make the friction stub positioned toward the positioning hole, then it is easy and convenient to press the lamp base and the lamp socket together owing to the fitness between the two elements. Due to the frictional force between the expanded end of the friction stub and the positioning hole, it can be assured that the stable condition between them will be sustained without being affected by external nature forces or other factors after assembled. On the other hand, if the lamp base and the lamp socket have to be separated, it is only necessary to push on the fore end of the friction stub which is exposed out of the lamp socket, to make the lamp base slightly dislodged from the lamp socket, thus it is easy to apply a force on the lamp base to extract it out of the lamp socket for replacing a new lamp base.
It is therefore another object of the present invention to provide, in addition to the stable combining relationship resulted between the lamp socket and the lamp base, a lamp socket and a lamp base which can be slightly separated from each other for easily applying a force on the lamp base.
It is yet another object of the present invention, in which the structure, according to the present invention, can be applied to the stable combination between a conglomeration of twin or multiple lamp bases and a corresponding shaped conglomeration of lamp sockets, subsequently to solve the defeats of not easily connected to each other due to the dimensional interference between each lamp base and the correspondent lamp socket of the combination of the conventional multiple lamp bases and multiple lamp sockets.
It is yet further another object of the present invention to provide a combining structure of multiple twin lamp bases and multiple lamp sockets, in which two vertical grooves are respectively formed in the middle portions of two outer surface of the multiple lamp sockets, and an additional inverted U shaped clip made of plastic has a lobe on each of the tips of its two branch legs. Thus, by using the present invention, after the twin lamp bases and the twin lamp sockets are pressed together, the inverted U shaped clip can bridge across the middle portion of the two lamp bases to make the lobes of the two branch legs sliding along the vertical grooves on the two outer surface of the lamp sockets until they arrive at the bottom of the lamp sockets. Then the separated branch legs come to close again, so that the two lobes are attached against the bottom surface of the lamp sockets and the lamp bases and the lamp sockets are tightly combined together by this inverted U shaped clip. On the other hand, such two lobes can be pull off the bottom surface of the lamp sockets and dismounted from the lamp bases and lamp sockets, then the lamp bases can be pull out from the lamp sockets by an appropriate force.